Field of the Invention
The present invention relates to a grinding apparatus for grinding a plate-shaped workpiece to reduce the thickness of the plate-shaped workpiece to a desired thickness.
Description of the Related Art
A grinding apparatus for grinding a plate-shaped workpiece essentially includes a chuck table for holding the plate-shaped workpiece and grinding means for grinding the plate-shaped workpiece held on the chuck table. The grinding means includes a spindle and a grinding wheel mounted on one end of the spindle. The grinding wheel includes a plurality of abrasive members arranged annularly. The grinding wheel is rotated by rotating the spindle, and the abrasive members are brought into contact with the plate-shaped workpiece to thereby grind the plate-shaped workpiece until a desired thickness is reached.
As one type of such a grinding apparatus, the grinding apparatus is composed of rough grinding means for performing rough grinding to a plate-shaped workpiece and finish grinding means for performing finish grinding to the plate-shaped workpiece rough-ground. In this type of grinding apparatus, the two pieces of grinding means are required, so that the size of the grinding apparatus is increased. To cope with this problem, there has been proposed a grinding apparatus including a rough grinding wheel and a finish grinding wheel mounted on a common spindle to perform rough grinding and finish grinding (see Japanese Patent Laid-open No. 2014-042959, for example). In this grinding apparatus, the rough grinding wheel and the finish grinding wheel larger in diameter than the rough grinding wheel are concentrically mounted on a wheel mount to thereby configure a double wheel structure. Accordingly, as compared with another structure such that the rough grinding wheel and the finish grinding wheel are arranged side by side, an increase in size of the apparatus can be prevented in this double wheel structure.